The long-term goal of this project is to examine the biochemical, behavioral, endocrinological and toxicological effects of drugs which influence catecholaminergic neurons in the central nervous system. Particular attention will be directed toward the actions of dopaminergic agonists and antagonists on nigrostriatal, mesolimbic and tuberoinfundibular neuronal systems. Projects will involve experiments on: 1. Drug-induced alterations of dopaminergic receptor sensitivity. 2. Control of the anterior pituitary by dopaminergic neurons. 3. Self-administration of direct and indirect acting dopaminergic agonists. BIBLIOGRAPHIC REFERENCES: Moore, K. E. and Goodale, D. B.: 6-Hydroxydopamine-induced dopaminergic receptor supersensitivity: Studies with D- and L-dopa. In: Chemical Tools in Catecholamine Research. Vol. 1. 6-Hydroxydopamine as a Denervation Tool in Catecholamine Research. ed. G. Jonsson, Ch. Sachs and T. Malmfors. pp. 343-347, American Elsevier, New York, 1975. Gudelsky, G. A. and Moore, K. E.: Differential drug effects on dopamine concentrations and rates of turnover in the median eminence, olfactory tubercle and corpus striatum. J. Neural. Transmission 38: 95-105, 1976.